Switch box



Feb. 16 1926.

H. G. BAXTER SWITCH BOX Filed March 11, 1919 2 Sheets-Sheet l INVENTORHam/0 6. Baxfer WITNESSES:

) AMW ORNEY' Feb. 16 1926. 1,572,878

H. G. BAXTER SWITCH BOX Filed March 11, 1919 2 Sheets-Sheet 2 52 flarg iwar v BY Patent ed Feb. 16, 1926.

UNITED STATES "PATENT OFFICE.

IHLAIBOILID G. BAXTER, OF BALDWIN, NEW YORK, ASSIGNOR T WESTINGHOUSEELEC- TRIO & MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SWITOH BOX.

Application filed March. 11, 1919. Serial No. 281,912.-

To all whom it may concern:

Be it known that I, HAROLD Gr. Baxrnn, a subject of the King of England,and a resident of Baldwin, in the county of Nassau and State of NewYork, have invented a new and useful Improvement in Switch Boxes, ofwhich the following is a specification.

My invention relates to switch boxes and particularly to safety-firstswitch boxes.

One object of my invention is to provide a switch box having a rotatablesnap switch therein that shall be adapted to be actuated by areciprocating lever arm.

Another object of my invention is to provide a switch box having a latchfor the door thereof that shall be so interlocked with the switch thatthe latch and, consequently,

the door cannot be opened when the switch is closed and the switchcannot be closed when the door is open.

A further object of my invention is to provide a safety-first switchbox, of the above indicated character, that shall be simple andinexpensive to construct and efective in its operation.

In practicing my invention, 11 provide a spring-actuated rotatable snapswitch that 1s disposed in a box or casing having a door to the fusecompartment thereof. The switch is provided with an oscillating leverarm external to the box for actuating the same, and the door is providedwith a latch for holding the same in its closed position. A cam memberis associated with the switch and is so interlocked with the latch thatthe latter cannot be operated to permit opening the door so long as theswitch is in its closed position and the switch cannot be thrown to itsclosed position when the door is open.

Figure 1 of the accompanying drawings is a front elevational View, withparts broken away, of a switch box embodying my invention, and Fig. 2 isa side view, artially in section and partially in elevation, of theswitch box shown in Fig. 1. Fig. 3 is a side elevation of the mechanismshown in Fig. 2 showing the switch and associated parts in 0 enposition.

A switc box 1 is constructed of metal or other fireproof material and isprovided with a door 2 to the portion thereof adjacent fuses 3 locatedtherein. An insulat-. ing panel board 4 is disposed in the box 1 and isadapted to support stationary contact members 5 and 6 and fuse terminals7 and 8. The panel board 4 is also adapted to support standards 9 and 10upon which is mounted the rotatable member 11 of the switch. A handle 12extends from one side of the box for the purpose of actuating theswitch.

Bridging contact members 13 are mounted on the member 11 and are adaptedto engage the stationary contact members 5 and 6. A. cam member 14 isalso mounted on the member 11 and a rod 15, which rotates with thehandle 12, is disposed therein and is relatively movable with respectthereto. A lever arm 16 is mounted on, and turns with, the rod 15 and isprovided with aprojection 17 that is adapted to actuate two latchmembers 18 and 19 when the handle approaches'its extreme closed and openpositions, respectively. The latch members 18 and 19 are connected by aspring 23 which holds the said members in engagement with the peripheryof the cam 14. A spring 20 isdisposed around a portion of the rod 15 andis connected, at one of its ends, to the member 11 through the cammember 14:, and, at its other end, to the lever arm 16.

The operating lever 12 is connected, through a sleeve 21, to the rod 15.The cam member 14 is provided with cut-away portions 22 and 22' whichform'contact faces 22 and 22 and 22 and 22 respectively, the faces 22and 22 serving to limit rotary movement of the cam 14- by reason oftheir alternate engagement with the stationary stop member 22 which issupported by the base 4. The contact faces 22 and 22 are adapted torespectively engage the latch faces 18 and 19 which are 14, to which itis attracted, ten ing to rotate the cam in a similar direction. Rotarymovement of the cam is revented by reason of the engagement of thecontact face 22 with the latch face 19 until after the projection 17 hasengaged the extension 33 carried'by the latch'member 19 and has so movedthe latch member that the latch face 19 no longer interferes with therotary movement of the cam. At such time the cam rotatescounter-clockwise through 90 with a snap, due to the tension of the.spring, and is stopped by reason of the engagement of the contact face22 with the stop member 22. The contact face 22 will then occupy aposition behind the latch face 18, as indicated in Fig. 3, and preventsclockwise movement of the cam 14 and bridging switch 6 to open positionuntil after the lever 16 has been moved counter-clockwise a sufiicientdistance to move the latch mem ber 18 clear ofthe contact face 22. Thecam 14 will then rotate in a clockwise direction until the contact face22 v engages the stop member 22*, in which position the bridging switch6 will be held in open position. With this arrangement of elements itwill be seen that an oscillatory movement of the operating handle 12will cause similar movement of the bridging switch, and that the switchis moved to open and to closed positions with a snap.

A cam member 24 is disposed on the rod 15 and has two grooves 31therein. The grooves 31 are concentric with the hinge of the door 2 whenthe cam member 14 is in predetermined open positions. A latch member 25is carried by the door and is so actuated by a spring 26 that itnormally latches the door 2 n its closed position. The latch is providedwith a rojection 27 and an operating knob 28. The operating knob 28extends through a slot 29 in the door 2 to permit the latch 25 to bemoved to such posi tion as to permit the door 2 to be opened when theswitchis in its open position only.

The latch 25 has a projection 30 thereonthat registers with the grooves31 of the cam member 24, under predetermined conditions, to permitrelative movement of the door and the switch. That is, the projection 30is movable in the grooves 31 to ernit opening of the door only when theswitch is in its'o en position and it so engages the grooves t at theswitch cannot be thrown to its closed position until the door is fullyclosed. A stop 35 is provided for retaining the pro'ection 30 in thegroove 31 so long as the door is open. The projection 27 of the latch 25is adapted to engage the portion 34 of the cam member 24 to prevent theoperation of the latch and thus the opening of the door when the switchis in the closed position, as shown in the drawings. However, when theswitch is in its open position, the cam member 24 will assume suchposition as to permit the projection 27 to move to such position thatthe latch is in its open position and the door may be opened, thuspermitting the portion 30 of the latch to assume the position shown inthe broken lines in Fig. 2 of the drawings.

When it is desired to operate the switch, the lever arm 12 is moved tosuch position that the projection 17 on the lever arm 16 locking meansbetween the switch and the latch member of the door, may be actuated byan oscillating handle.

My invention is not limited to the particu lar structures illustrated,as it may be variously modified without departing from the spirit andscope of the invention, as set forth in the appended claims. 1

I claim as my invention: 1

1. The combination with a casing having an opening therein and a doorfor the opening, of a rotatable switch, a shaft therefor, an oscillatinghandle for actuating the switch, a latch for the door movable withrespect thereto, and a cam member mounted on the shaft and inoperable bythe latch for so cooperating with the latch and the switch that the dooris prevented from being opened when the switch is closed and the switchis prevented from being closed when the door is open.

2. The combination with a casing having an opening therein and a doorfor the opening, movable to open and to closed position,

of a rotatable switch mounted on the casing and o erable from withoutthe' casing, a

shaft or the switch, a cam mounted on the shaft and movable with theswitch, a latch for the door movable with respect thereto, and movabletherewith and so interlocked with the cam that operation of the switchis prevented by the latch so long as the door occupies a positionintermediate closed position and open position;

3. The combination with a housin having an opening therein and a doorfor t e opening, of a rotatable switch, a latch for the door carried bythe door and having an extension swinging inwardl into the hous ing whenthe door is move to open osition and a cam member within the housmg andinofigrable by the latch for so co-o eratin wit the latch and the switchthat t e latc 1s prevented from being moved to release the door when theswitch is. closed and the switch is prevented from being closed when thedoor is open.

4. Switch mechanism comprising a casing having fan opening therein, a,hinged door for the opening, a rotatable switch within the casing, aninterlocking member having a convex surface concentric to the axis ofthe switch and a concave surface concentric to the axis of the doorhinge, and a latch member movably mounted upon the door and having oneportion engaging the convex surface, when the switch is in closedposition, for preventing opening movement of the latch and anotherportion for engaging the concave surface, when the door is open, forpreventing closing movement of the switch.

5. The combination with a housing having an opening therein and a doorfor the opening, a rotatable switch within the housing, a rotatable camwithin the housing and movable with the switch, and a latch carried bthe door and movable with respect thereto for swinging into the housingwhen the door is opened into interlocking engagement with the cam, thesaid cam and latch being so arranged as to prevent operation of the camby the latch and to prevent opening movement of the cover when theswitch is closed and closing movement of the switch when the cover isopen.

In testimony whereof, I have hereunto subscribed my name thistwenty-eighth day of February, 1919.

HAROLD G. BAXTER.

